Coking of heavy oils



Jan. 22, 1935. w. P, A JR 1,988,644

COKING OF HEAVY OILS Filed Feb. 28, 1929 ATTORNEYS Patented Jan. 22, 1935 PATENT, OFFICE come on HEAVY OILS William P. Arnold, In, Houston, Tex assignor to Sinclair Refining Company, New York, N. Y.,

a corporation of Maine Application February 28, 1929, Serial No. 343,573

This invention relates to improvements in the coking of heavy oils, such as crudes, topped crudes, flux oils, other residual oils and the like. More particularly, this invention relates to improvements in such coking operations in which 'a charge of coke is formed and deposited within an externally unheated coking receptacle from which this cokeproduct must be discharged. Commercially, lump coke is more valuable than coke fines. The improvements of this invention assist particularly in minimizing the production of coke fines in such coking operations.

The invention is particularly useful in connection with the operations described in applications Serial No. 340,996 filed February 18, 1929 and Serial No. 341,214 filed February 19, 1929 by Harry L. Pelzer, now Patents No. 1,831,719 and No. 1,873,024, respectively, and application Serial No. 347,533 filed March 16, 1929 by George H. Taber, Jr., and Edward W. Isom, now Patent No.

1,873,068, but it is also of more general application.

Most of the fines produced in such coking operations are produced, not during the coking operation proper, but during the discharge of the coke product from the coking receptacle, and

such fines are produced by the disintegration of what otherwise would be lump coke. For example,'certain advantageous methods of discharging the coke product from the coking receptacle with the production of but a relatively small amount of fines are described in applications Serial No. 344,952 filed March 7, 1929 by Oliver F. Campbell and Eugene C. Herthel, now Patent No. 1,872,884, and Serial No. 345,016 filed March 7, 1929 by Willis S. Gullette, now Patent No.

1,872,938, but even with the best available methods of discharging the coke product, the production of some coke fines seems to be inevitable.

This invention provides for the conversion 01 the coke fines inevitably produced as an incident to such coking operations to commercially valuable lump coke in a particularly advantageous manner.

According to this invention, coke .fines, produced in a preceding cycle of the same coking operation, for example, are charged to the coking receptacle before the coking operation proper is initiated and the coking operation is then carried out. without external application of heat to the coking receptacle. If the coke fines contain much very fine material, sumcient of the heavy 011 stock to be reduced to coke is, with advantage, supplied to the coking receptacle with the coke fines before the coking operation proper is initiated to hold the fines in the coking receptacle when the coking operation is initiated. As the coking operation proceeds, the coke fines are incorporated in the charge of coke accumulating in the coking receptacle. Thus, when the coking 6 operation is carried out as a continuous repetition of the same operating cycle, the fines produced in each cycle are recharged in the next cycle and the ultimate coke product is, substantially completely, commercially valuable lump coke. Withl0 can be charged to the coking receptacle together with, coke fines produced in the preceding cycle of the same coking operation to be converted to commercially valuable lump coke.

Coke fines cannot be handled in this manner in the conventional coke still because, with external application of heat, the still bottom would become overheated very shortly after the operation was initiated. This difiiculty, however, is avoided in carrying out this invention byvsupplying the heat necessary to the coking operation internally only, as described, for example, in Patents No. 1,831,719, No. 1,873,024 or No. 1,873,068, mentioned above.

No apparatus of novel or unusual design is required to carry out the process of the invention.

However, the accompanying drawing, diagrammatically illustrates in elevation and partly in section, one form of apparatus adapted for the practice of the invention. The apparatus illustrated 30 in the drawing comprises a part of the apparatus illustrated in Patent No. 1,873,024 above mentioned, but it is intended and will be understood that the invention can be carried out in other and different forms of apparatus.

Referring to the drawing, the chamber 1, thecoking receptacle. A-charge of heavy oil in the receptacle 1, may be internally heated, for example, by supplying a light oilthrough connection 2, to a heating coil 3, located in the heat ing flue of the heating furnace 4, subjecting this light oil to a vapor'phase cracking operation in the heating'coil 3, and discharging the hot vapor mixture from the cracking operation through connection 5 into the charge of oil to be reduced to coke in the coking receptacle. The heavy 011 stock to be reduced to coke may be introduced to the coking receptacle through connection 6, and hot vapors may be taken oil? from the coking receptacle through connection 7. The cokefines Q to be incorporated in the'final coke product may be admixed with a portion of the heavy oil to be reduced to coke and the mixture introduced into the coking receptacle through connection 6, as the initial charge. The coking receptacle may advantageously be lagged or thermally insulated and provided with suitable means, removable heads or the like, for discharging the coke product formed therein.

The heating coil 3 may be heated uniformly and efiiciently by recirculating furnace gases which have passed over the heating coil to the combustion zone by means of the fan 8 and by preheating the air required for combustion. The air required for combustion may be forced through the preheater 9 by the fan 10.

I claim:

1. In the coking of heavy oils, the improvement which comprises charging coke fines to a coking receptacle before the coking operation proper is initiated, supplying a heavy liquid oil to the coking receptacle and reducing the charge, including coke fines and heavy liquid oil, to dry lump coke by supplying heat internally to the charge within the coking receptacle.

2. In the coking of heavy oils, the improvement which comprises charging coke fines together with an initial supply of the heavy liquid oil to be reduced to coke to a coking receptacle before the coking operation proper is initiated, and reducing the mixture of coke fines and heavy liquid oil to dry lump coke by supplying heat internally to the charge within the coking receptatcle.

WM. P. ARNODD, JR. 

